P097 Sleep, Fatigue and Depression in Young Autistic Adults

INTRODUCTION: Poor sleep and fatigue are common in autistic adolescents and adults, who also experience increased depression compared with the general population. We examined the relationships between sleep quality, fatigue and depression in autistic young adults. METHOD: Participants were 114 autistic young adults (15-25 years) from the Study of Australian School Leavers with Autism baseline survey (n=112; 57.1% male). From the survey we examined relationships between age, sex and the Autism Quotient-Short (AQ-S; autistic traits), Pittsburgh Sleep Quality Index (PSQI), Hospital Anxiety and Depression Scale (HADS-D) and the Flinders Fatigue Scale (FFS) using Spearman’s Correlation. We then investigated whether FFS mediated the relationship between the PSQI and HADS-D (PROCESS macro; 1000 bootstrapped resamples). Due to missing data, not all individuals are included in reported analyses. RESULTS: 38% (n=83) of participants had depression, 57% (n=94) poor sleep, and 36% (n=73) fatigue. HADS-D was positively associated with PSQI (p<.001) and FFS (p<.001). Increased PSQI and FFS were associated with sex (female) and increased AQ-S (all p<.01). The full mediation model accounted for 25% of variance in depression (p<.001) with a significant indirect effect of sleep quality on depression through fatigue. The direct effect of sleep quality on depression was not significant after fatigue was included in the model. CONCLUSIONS: Findings indicate poor sleep and fatigue play a role in the maintenance of depression in autism. Further replication in larger and longitudinal cohorts is needed. Like non-autistic individuals with depression, sleep and fatigue may be important treatment targets for treating depression in autism.